In a display part with a liquid crystal module, hitherto used in a variety of display devices, such as liquid crystal television or a mobile phone, a gap of 0.5 to 1 mm is provided between the surface of a panel of a liquid crystal module and a transparent protective cover, such as an acrylic plate, placed thereabove. If, in this structure, the protective cover is broken by shock from outside, the liquid crystal module may remain unaffected.
In such air gap structure, a liquid crystal panel of the liquid crystal module, an air layer of the air gap and the protective cover of glass or plastics, are layered in this order. These are different in refractive indices. Thus, light reflection occurs at an interface between the liquid crystal panel and the air layer, an interface between the air layer and the protective cover and at an interface between the protective cover and outside atmosphere, thus occasionally lowering luminance or contrast ratio due to light scattering. For example, display on the liquid crystal panel may not be seen with ease under insolation.
To cope with such problem, there is known a technique in which an air gap structure is not used and a transparent optical resin whose refractive index is close to that of glass or acryl is sealed into between the liquid crystal panel and the protective cover and cured in situ by UV light illumination. In case the air gap is filled with the optical resin, the interface between the liquid crystal panel and the air layer or the interface between the air layer and the protective cover is substantially eliminated and no light reflection or scattering occurs at these interfaces. It is thus possible to make improvement in contrast ratio or luminance of the display on the liquid crystal panel appreciably.
If, in such optical resin charged structure, the optical resin is charged into between the liquid crystal panel and the protective cover, it is demanded that the optical resin is charged in a state free from mixing of air foam. It is also demanded that the optical resin is not exuded out of the gap between the liquid crystal panel 2 and the protective panel 3 so as not to affect neighboring elements.
Methods and devices for coating and curing the optical resin have also been developed (see Patent Document 1). In these devices, a transparent optical resin is coated in the vicinity of outer lateral side edges of the protective cover retained by a loader. This optical resin is semi-cured to form a dam. The optical resin is coated on the entire surface of the protective cover, which is topsy-turvied and retained. A liquid crystal panel is placed facing and contacted with the surface of the protective cover coated with the optical resin to spread out the resin in a gap between the two panels. At this time, the spread-out resin is stopped by the dam formed in the vicinity of the outer lateral side edge of the protective cover, thus preventing the resin from exuding from the gap between the two panels. After the optical resin has been spread out over the entire areas of the gap between the liquid crystal panel and the protective panel, curing light for the optical resin is illuminated on the entire surfaces to cure the optical resin.